[TowerTalk] Bent mast.

Bob Nygren N3RN wrote:
>
> Greetings,
> First, let me save you a few bytes.
>
> "WE TOLD YOU SO!!!"
>
> The discussion about galvanized water pipe being a poor choice
> for a mast was not ignored. But when I put the tower up some 20 years
> ago I didn't know any better. After Monday nights blow, I know better!
> What I'd appreciate now is some advice regarding how to get the
> antennas down safely.
> The tower is only 40 feet, mounted in concrete and bolted to the
> house at 8 feet and at the peak. The top of the tower is about 15
> feet above the house. Appox 9 feet of mast is in the tower. The
> remaining 12 feet or so is loaded with 205 elements of various VHF/UHF
> antennas. At the botton is 5 el on 6 meters. ( I can get this off OK)
> At the top is 4 x 23 element F9FT's for 1296 and a 33 el looper for 903.
> I'd like to not destroy these guys!
> If I cut the mast at the top of the tower, would it fold over
> gently or snap off? ( I know Murphys Law.)
> Any other thoughts or ideas would be appreciated.
>
> Thanks in advance,
>
> Bob N3RN <rnygren@epix.net> FN11WH (no longer 50 - 1296)
>
> --
> FAQ on WWW: http://www.contesting.com/towertalkfaq.html
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I have seen bent masts before. Generally sawing them off is dangerous
and a lot of work. It is only slightly safer to use a gin pole. I have
used a piece of 10' electrical conduit to extend my reach to help tie a
half hitch around the mast as far up and out as you can then tie the
loose end of the gin pole rope onto the mast above the place you want to
cut it off. Keep tension from the ground on the line up through the gin
pole and out to the top of the mast for support while you are cutting.
Depending on where you hook on to it, you may want to leave the 6 meter
antenna on it to help keep the center of gravity below the half hitch.
Bent Mast
/
Gin Pole /
________/ <= half hitch here
| /
| /
| /
| /
| /
| /
| / <= rope tied here
|/ <= cut here
| | <= top of tower
| |
One thing that I have found useful is a chain style vise grip firmly
clamped on the cut off mast to give you a place to hold and a way to
control the twist of the mast during the final cut off and lowering.
Generally you have to have two people at the top of the tower to help
man handle the cut off operation.
Another option is you might be able to pick the whole thing out at once
using a long heavy duty gin pole, but controlling the center of gravity
is the important part to keep the whole thing from "turtling" upside
when you get it free.
--
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